Dark data is the information your company collects but never uses, often...

https://holdenssplendiddigests.zenbloomer.com/posts/what-should-we-delete-first-when-cleaning-up-dark-data

Dark data is the information your company collects but never uses, often sitting idle on servers or cloud storage. It can make up 55% of all stored data, driving up costs and creating risks from outdated or unsecured files